In a disk drive used as an auxiliary device for an information processing system, any of various disk-shaped storage media (referred to as the storage disk in this specification) such as a magnetic disk, an optical disk and a magneto-optic disk is rotated at high speed, while a head section is caused to perform the tracking operation following a multiplicity of recording tracks formed concentrically on the recording surface of the recording disk thereby to read and write data. The tracking performance of the head section depends on the positioning accuracy in the servo control operation of an actuator supporting the head section. Especially in recent years, with the remarkable increase in the recording density of the storage disk, demand has become considerably exacting for the positioning accuracy of the actuator.
For the actuator to perform the highly accurate tracking operation, the external disturbances affecting the operation of the actuator are required to be minimized. For example, the air flow generated around the storage disk in high-speed rotation becomes turbulent by bombarding the actuator and may cause vibration of the actuator and the storage disk. Especially in a configuration like a hard disk drive in which the actuator has a suspension arm extending along the recording surface of the storage disk and rotatable about a supporting shaft, the suspension arm is vibrated by the turbulent air flow and can adversely affect the positioning accuracy of the head and the dimensional accuracy of the gap between the head and the recording surface of the disk.
To cope with this problem, various disk drives have been proposed which include an air-flow adjusting mechanism for adjusting the air flow generated around the storage disk rotating at high speed. The specification of U.S. Pat. No. 5,854,725, for example, discloses a hard disk drive having a plurality of guide members mounted on the surface of the arm of the actuator. These guide members are each a small piece in the shape of a streamline or a wedge and are fixed on the upstream or downstream side of the arm surface by an adhesive or the like. Each guide member smoothly guides the air flow around the storage disk rotating at high speed, along the outer surface of the actuator arm, and thus converts the air flow into a laminar flow thereby reducing the effect that the vibration caused by the air flow has on the arm.
Also, the specification of U.S. Pat. No. 5,446,612 discloses a hard disk drive wherein a wing is formed on the arm of the actuator. The wing of the arm, receiving the air flow caused by the rotation of the storage disk, generates a force whereby the head at the forward end of the arm approaches the disk. As a result, the head bearing operation is stabilized and the dimensional accuracy of the gap between the head and the recording surface of the disk is improved.
Japanese Unexamined Patent Publication (Kokai) No. 2001-23347 discloses a hard disk drive having air rectification wings inserted between a plurality of storage disks and arranged at predetermined spatial intervals over the range of head movement downstream of the head at the forward end of the arm of the actuator in the direction of disk rotation. The air rectification wings have a streamlined section for rectifying the air flow between the disks in the vicinity of the arm and thus suppresses the vibration of the disk and the arm. In similar fashion, Japanese Unexamined Patent Publication (Kokai) No. 2000-228079 discloses a hard disk drive having comb-shaped rectification members inserted between a plurality of arms of the actuator.
Also, Japanese Unexamined Patent Publication (Kokai) Nos. 5-101557 and 5-100061 disclose a hard disk drive for reducing the shock at the time of starting or stopping the operation of the arm, by mounting an elastic member or a buffer member on the arm of the actuator or covering the arm rotation shaft with a damping member.
In the conventional hard disk drive, for example, a through hole or a notch is generally formed at a predetermined position of the arm to reduce the weight of the suspension arm and thus to reduce the moment of inertia of the suspension arm when the actuator is in operation. With this configuration, the through hole or the notch, as the case may be, causes a great turbulent air flow along the outer surface of the suspension arm, which in combination with the reduced weight of the suspension arm, may vibrate the suspension arm more readily.
In the various conventional air-flow adjusting mechanisms described above, it is difficult to directly suppress the turbulence of the air flow caused by the through hole or the notch formed in the suspension arm in order to reduce the moment of inertia. Further, with the increase in the number of suspension arms, the configuration of the air-flow adjusting mechanism is more complicated, with the result that the manufacturing process may be complicated or the production cost may increase. Also, it may be that the air-flow adjusting mechanism described above fails to work effectively on the other disk drives having no suspension arm.
An object of the present invention is to provide a disk drive for writing and reading data into and from a storage disk, comprising an inexpensive and easily mountable air-flow adjusting mechanism for adjusting the air flow caused around the storage disk rotating at high speed, and thus capable of suppressing, among others, the effect that the vibration caused by the air flow has on the actuator.
Another object of the invention is to provide a disk drive comprising a suspension arm extending along the recording surface of a storage disk and rotatable about a supporting shaft and an air-flow adjusting mechanism capable of directly preventing the turbulence of the air flow caused by the through hole or the notch formed in the suspension arm to reduce the moment of inertia.
Still another object of the invention is to provide a method of producing such a disk drive easily at low cost. A further object of the invention is to provide a thin-film member capable of being incorporated, as an air-flow adjusting mechanism, in a disk drive.